Deprecated: The each() function is deprecated. This message will be suppressed on further calls in /home/zhenxiangba/zhenxiangba.com/public_html/phproxy-improved-master/index.php on line 456
AU666934B2 - Surface-treated metal sheet of high durability and a process for manufacturing the same - Google Patents
[go: Go Back, main page]

AU666934B2 - Surface-treated metal sheet of high durability and a process for manufacturing the same - Google Patents

Surface-treated metal sheet of high durability and a process for manufacturing the same Download PDF

Info

Publication number
AU666934B2
AU666934B2 AU38296/93A AU3829693A AU666934B2 AU 666934 B2 AU666934 B2 AU 666934B2 AU 38296/93 A AU38296/93 A AU 38296/93A AU 3829693 A AU3829693 A AU 3829693A AU 666934 B2 AU666934 B2 AU 666934B2
Authority
AU
Australia
Prior art keywords
metal sheet
layer
paint
treated metal
sheet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
AU38296/93A
Other versions
AU3829693A (en
Inventor
Toru Kameya
Mitsuru Shimamura
Hisanori Shimizu
Katsuaki Takano
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Taiyo Steel Co Ltd
Original Assignee
Taiyo Steel Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Taiyo Steel Co Ltd filed Critical Taiyo Steel Co Ltd
Publication of AU3829693A publication Critical patent/AU3829693A/en
Application granted granted Critical
Publication of AU666934B2 publication Critical patent/AU666934B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/16Articles comprising two or more components, e.g. co-extruded layers
    • B29C48/18Articles comprising two or more components, e.g. co-extruded layers the components being layers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/14Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to metal, e.g. car bodies
    • B05D7/16Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to metal, e.g. car bodies using synthetic lacquers or varnishes
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00Layered products comprising a layer of metal
    • B32B15/04Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B15/08Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B32B15/085Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin comprising polyolefins
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/50Multilayers
    • B05D7/56Three layers or more
    • B05D7/58No clear coat specified
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00Layered products comprising a layer of metal
    • B32B15/04Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B15/08Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04Interconnection of layers
    • B32B7/12Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00Processes for applying liquids or other fluent materials
    • B05D1/26Processes for applying liquids or other fluent materials performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface
    • B05D1/265Extrusion coatings
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2507/00Polyolefins
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2507/00Polyolefins
    • B05D2507/005Polyolefins modified
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2601/00Inorganic fillers
    • B05D2601/20Inorganic fillers used for non-pigmentation effect
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2309/00Parameters for the laminating or treatment process; Apparatus details
    • B32B2309/08Dimensions, e.g. volume
    • B32B2309/10Dimensions, e.g. volume linear, e.g. length, distance, width
    • B32B2309/105Thickness

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)

Description

P/00/011 Regulation 3.2
AUSTRALIA
Patents Act 1990 ORIGINAL 6 6 3 4 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: SURFACE-TREATED METAL SHEET OF HIGH DURABILITY AND A PROCESS FOR MANUFACTURING THE SAME
D
The following statement is a full description of this invention, including the best method of performing it known to us: GH&CO REF: P22749-A:PJW:RK 1A BACKGROUND OF THE INVENTION Field of the Invention: The present invention relates to a surface-treated metal sheet of high durability and to a process for its manufacture. At least preferred embodiments of the metal sheet of the present invention hive high levels of corrosion resistance, weatherability and formability and are intended for use principally as a material for use in the construction of an outdoor structure.
Description of the Prior Art: It has hitherto been usual to manufacture a surface treated and coated metal sheet as a material for an outdoor structure, or article by employing the continuous application of a paint, the continuous lamination of a film, or the continuous hot-melt coating on a metal sheet, such as a hot dipping galvanised steel sheet conforming to JIS G-3302, a zinc electroplated steel sheet conforming to JIS G-3313, a steel sheet galvanised with a 5%Al-Zn alloy which conforms to JIS G-3317, a 20 steel sheet plated with a 55%Al-Zn alloy, a steel sheet S*plated with aluminum, an aluminum sheet, or a stainless steel sheet, as described below: .a S:'9749 1 '"nn Continuous Application of a Paint: A metal sheet which has been given surface treatment is continuously coated with a paint by, for example, a roll coater to make a two-coat and two-bake colored metal sheet; Continuous Lamination of a Film: A metal sheet which has been given chemical surface treatment is undercoated with, for example, an adhesive, and after it has been dried, a resin film is continuously laminated thereon to make a laminated metal sheet; and Continuous Hot-Melt Coating: The chemically treated surface of a metal sheet is undercoated with an epoxy resin paint, and is continuously coated with a polyolefin resin and a modified poly- 1. .'1i olefin resin extruded from an extruder through a T-die to make a resin-coated metal sheet.
The surface-treated and coated metal sheet manufactured as hereincbove described has corrosion resistance, weatherability, formability, decorative property, etc., and is stable in quality. Moreover, it does not call for any further coating after its forming into a particular shape, or its use at the site of construction. Therefore, it has been used widely as a material for the construction of an outdoor structure, etc.
While any such surface-treated and coated metal 2 sheet is required to have certain properties including weatherability, corrosion resistance, formability and scratch resistance, very high levels of such properties have recently come to be required of the sheet, so that it may withstand exposure to a severe environment, including a change of environment caused by acid rain, particularly insofar as it is used to construct a structure which is required to be maintenance-free.
As far as weatxerability is concerned, it has. been found that a fluororesin paint is suitable for maintenancefree application. A steel sheet coated with a thick film of vinyl chloride; and a steel sheet coated with a polyethylene resin have, for example, been used as materials .".having a high level of corrosion resistance.
It has, however, been found that a steel sheet coated with a fluororesin paint and having excellent weatherability as stated above is easily scratched during its forming, such as bending or roll forming, or during its handling for use at the site of construction, since a film of the paint with which it is coated has a thickness which is usually as small as from 25 to 35 microns, and a low degree of hardness, and that the sheet is likely to have a lower degree of corrosion resistance in its scratched, or formed portion. Therefore, it has usually been necessary to employ a protective film, or repair any scratched 3 portion after the work of forming. Studies have been made to solve those problems and form a coating film of a fluororesin paint having a high degree of hardness and thereby achieving an improved scratch and wear resistance without the sacrifice of the formability of the coated metal sheet, or the adhesion of the film, while retaining the advantage of the fluororesin paint. As a result, it has .been proposed that glass fibers be added to a fluororesin paint with which a metal sheet is coated, as taught in Japanese Patent Publication No. Sho 60-7946 entitled "Process for Manufacturing a Coated Metal Sheet of High Durability", or Japanese Patent Application laid open under No. Sho 61-237636 entitled "Coated Steel Sheet".
According to the disclosure of those publications, it is preferable for forming a good coating film that the glass to be added to the paint in the form of surfacetreated fibers.
We, the applicant of this application, have, however, found that even a film having a high degree of hardness as suggested above is not sufficient for protecting the coated metal sheet from being scratched during its forming into a particular shape, or during its handling S for use at the site of construction. We have found the rapid progress of local corrosion, or the so-called flowering, on a steel sheet coated with a fluororesin paint as 4 a result of its exposure to an actually prevailing environment. The addition of surface-treated glass beads is preferred to prevent such rapid and local flouring.
Despite these improvements, however, it has still been the drawback of the fluororesin-coated steel sheet having a high level of weatherability that the steel surface under the coating film is scratched during its forming, or its handling for use, since the film has a thickness which is as small as from 25 to 35 microns.
A steel sheet coated with vinyl chloride, or a polyolefin resin has a high degree of corrosion resistance, since a film with which it is coated has a thickness of 150 to 300 microns which is so large that, even if any scratch may be made during the forming of the sheet into r a particular shape, or during its handling for use, it terminates within the film anl does not reach the steel surface, and since it is so high in formability that no cracking occur to any formed portion thereof. The energy which binds the atoms forming the molecules of any of those resins is, however, lower than the equivalent energy in the fluororesin, and lower than the energy of sunlight.
Therefore, those resins undergo rapid deterioration upon exposure to an actual outdoor environment, even if measures, *o including the control of their molecular weights, or molecular weight distribution, and the addition of a heat or 5 6 light stabiliser, may be taken to improve their weatherability.
SUMMARY OF THE INVENTION In view of the problems as stated above, it is an object of at least a preferred embodiment of the present invention to provide a surface-treated metal sheet of high durability having both weatherability and corrosion resistance which cannot be obtained by the mere use of a single manufacturing process selected from the continuous application of a paint, continuous lamination of a film, and hot-melting coating, and a process for manufacturing the same.
In a first aspect, the present invention provides a surface treated metal sheet of high durability comprising: a chemically treated metal sheet; an undercoat layer on the metal sheet, the undercoat :S layer comprising an organic resin paint containing a rust-inhibitive pigment; 20 an intermediate coating layer on the undercoat layer, the intermediate coating layer comprising a twolayer composite extruded film which comprises an adhesive S"layer of modified polyolefin resin on the undercoat layer and a polyolefin resin layer on the adhesive layer; and a topcoat layer on the intermediate coating layer, the topcoat layer comprising a topcoat paint selected o from an acrylic resin paint, a urethane resin paint, a polyester resin paint and a fluororesin paint.
In a second aspect, the present invention provides a process for manufacturing a surface treated metal sheet of high durability, the process comprising the steps of: subjecting a metal sheet to a chemical treatment to form a chemically treated metal sheet; applying an organic resin paint containing a rustinhibitive pigment onto the chemically treated metal sheet and drying the organic resin paint to form an undercoat layer on the chemically treated metal sheet; S:22749A/700 7 extruding a molten modified polyolefin resin and a molten polyolefin resin simultaneously in two layers from an extruder through a T-die to form an intermediate coating layer on the undercoat layer, the intermediate coating layer comprising an adhesive layer of the modified polyolefin resin on the undercoat layer and a layer of the polyolefin resin on the adhesive layer; and applying a topcoat paint selected from an acrylic resin paint, a urethane resin paint, a polyester resin paint and a fluororesin paint onto the intermediate coating layer and drying the topcoat paint to form a topcoat layer on the intermediate coating layer.
The metal sheet used as a base, or starting material may, for example, be a galvanised steel sheet, a steel sheet plated with an aluminum-zinc alloy, a steel sheet plated with aluminum, an aluminum sheet, or a stainless steel sheet. It is usually desirable to give chemical conversion treatment to the sheet surface to improve the adhesion of the undercoat layer to it. This chemical 20 conversion treatment is usually done by spraying a S* phosphoric acid type treating agent onto the sheet, or immersing it in such an agent, or coating it with a chromic acid type treating agent.
An undercoat paint is applied onto the chemically 25 treated surface of the sheet by, for example, a roll coater, and dried. The undercoat paint may be an epoxy, polyester, or other organic resin paint containing a rust-inhibitive S:22749A/700 pigment consisting mainly of a chromium compound, such as strontium or zinc chromate. The epoxy resin paint is, among others, preferred from the standpoint of corrosion resistance and also because of its good adhesion to the adhesive layer of a modified polyolefin resin. The triy kwa.
undercoat layer:ja a dry thickness of 1 to 20 microns.
Its drying ae carried out by heating the sheet to a temperature of 180 0 C to 240 0
C.
A modified polyolefin resin and a polyolefin resin which have been melted under heat are extruded from an extruder through a T-die, and pressed against the surface of the undercoat layer to form an intermediate coating layer in the form of a two-layer composite film consisting of an adhesive layer of the modified polyolefin resin and an intermediate layer of the polyolefin resin. The adhesive layer is employed to improve the adhesion between the undercoat and intermediate layers. The T-die extrusion of the two layers can be carried out by, for example, the method disclosed in our Japanese Patent Application laid open under No. Sho 57-203545.
Although it is usual to add heat and licht stabilizers, *a etc. to a polyolefin resin to prevent its ,xidation at a high temperature and its decomposition by ultraviolet light, this invention does not essentially call for the addition of any such heat or light stabilizer, since the topcoat 8 which will hereinafter be described protects the polyolefin resin from direct exposure to oxygen, ultraviolet light, etc. It is, however, preferable to add heat and light stabilizers in view of the possibility that the topcoat may be destroyed by scratching, etc. when a final product is used. A phenol, phosphorus, hindered phenol, or thioether compound is usually employed as the heat stabilizer, and a benzotriazole, benzophenone, acrylate, oxanilide, nickel complex, or hindered amine compound as the light stabilizer.
The intermediate coating layer preferably has a thickness of 50 to 500 microns. The adhesive layer may have a thickness of 5 to 30 microns, and the polyolefin resin layer on the adhesive layer may have a thickness of 45 to 495 microns. A polypropylene or polyethylene resin may be used as the polyolefin resin. The use of a polyethylene resin is, among others, recommended because of
S
its high extrudability, the high formability of the resulting surface-treated metal sheet, etc.
,20 When a heat stabilizer Irganox 1010) is used, it is likely that, after the topcoat is dried at a high temperature, the decomposition and evaporation of the volatile matter which the heat stabilizer contains may result in the formation of bubbles or blisters in the intermediate coating layer and thereby yield a surface- 9 treated metal sheet having an unacceptably poor surface rmpearance. It is, therefore, desirable to use a refined heat or light stabilizer having a low volatile content. It is alternatively possible to prevent the formation of such bubbles or blisters if, prior to the application of the topcoat, any impurities in the heat stabilizer are caused to undergo decomposition and evaporation by heating the intermediate coating layer so that the metal sheet temperature may reach a maximum of 240 0
C
to 280 0 C. The heat stabilizer is preferably employed in the amount of, say, 0.10 to 0.15% by weight of the polyolefin resin, so that no bubble or blister may be formed.
Then, the topcoat is applied onto the intermediate coating layer. In the event, however, that it is likely, *:15 depending on the polyolefin involved, that no satisfac- S* torily good interlayer adhesion may be obtained, the intermediate coating layer is modified by flame or corona discharge treatment, so that a large number of functional groups capable of conbining with hydrogen, such as hydroxyl, "20 carbonyl or carboxyl groups, may be .formed on the surface of the polyolefin resin layer, and raise its polarity to S. thereby improve its adhesion to the topcoat paint.
S..
The amount of heat in the range of, say, 3 to kcal/m2/min. is preferably employed for the appropriate flame treatment of the intermediate coating layer. If 10 2 it is smaller than 3 kcal/m /min., no satisfactorily improved adhesion can be obtained, and the use of heat 2 in any amount over 50 kcal/m /min. is undesirable, since the heat of combustion by a flame burner causes the yellowing and deterioration of the resin, and also since it adds to the cost of the treatment. The burner and the intermediate coating layer to be treated are preferably positioned at a distance of, say, 10 to 100 mm from each other, and usually at a distance of, for example, about 30 mm.
The corona discharge treatment can be carried out in a similar way to produce similar results.
A topcoat layer having excellent weatherability 9 is formed on the intermediate coating layer which has been treated as hereinab've described. It is preferable from 15 the standpoints of weatherability, scratch resistance, etc.
to form the topcoat layer of an acrylic, urethane or polyester resin paint, or a fluororesin paint. The topcoat layer is usually formed by the continuous application of the paint by a roll coater so as to have a dry thickness 20 of 5 to 35 microns. Its drying is carried out by heating so that the sheet temperature may reach a range of 200°C to 250 0
C.
Thus, there is obtained a surface-treated metal sheet of high durability according to this invention which is superior in weatherability, corrosion resistance, form- 11 ability, etc. compared to any standard two-coat and two-bake coated metal sheet made by the continuous application of a paint, any laminated steel sheet made by the continuous lamination of a film, and any resin-coated metal sheet made by the continuous heat-melt extrusion of a resin, while possessing the advantages of those three processes.
The invention will now be described with reference to exunples thereof and comparative examples.
EXAMPLES
Description will be made of the specific features and advantages of this invention by referring to three typical examples of this invention and the corresponding comparative examples. In Examples 1, 2 and 3 of this invention, flame, or corona discharge treatment was employed before the application of a topcoat to improve its adhesion..
*oo The conditions employed for surface treatment are shown in TABLE i, and the results of tests conducted in too TABLE 2.
5.o 12 1 0 C C Table 1(1) Metal Sheet Chemical Under coat (2) conversion Thickness Treatment Thickness Heating Heating (mm) Type temp. time Example 1 Zinc-plated steel sheet 0.35 Chromate Urethane-modified epoxy resin 5 p Roll coating 200°C coating paint containing a strontium chromate pigment 2 Steel sheet plated with a 0.50 Chromate Urethane-modified epoxy resin 7 p Roll coating 200°C 60 sec Ai-Zn alloy coating paint containing a strontium chromate pigment 3 Galvanized steel sheet 0.35 Chromate Urethane-modified epoxy resin 5 Roll coating 190°C 45 sec coating paint containing a strontium chromate pigment Comparative Zinc-plated steel sheet 0.50 Chromate Urethane-modified epoxy resin 5/ Roll coating 190 0 C 45 sec Example 1 coating paintcontaining a strontium chromate pigment 2 Steel sheet plated with a 0.35 Chromate Epoxy resin paint containing a 5s Roll coating 210°C Al-Zn alloy coating strontium chromate pigment 3 Zinc-plated steel sheet 0.80 Chromate Urethane-modified epoxy resin 7 p Roll coating 200°C coating paint containing a strontium chromate pigment 4 Golvanized steel sheet 0.35 Chromate Urethane-modified epoxy resin 5 p Roll coating 190°" 25 sec coating paint containing a strontium SI chromate pigment 13 0*.
5* S S S .55 *5 S Table 1 (2) Intermediate coating layer Top coAt(4) Adhesive Intermediate pieHatn Heig Type layer Iayer y ple Type Thickness Applied by Petn etn thickness thicnes temp. time Example 1 A composite filIm of l0,u I50P T-die Acryl-modified 2 0 p Roll coating 240 0 C 60 sec modified vinylidene fluoride polyethylene and resin paint polypropylene 2 A composite film of 1 5 pj 2 00 p T-die Acryl-modified 2 0Op Roll coating 240 0 C 70 sec modified vinylidene fluoride polyethylene and resin paint polyethylene_____ 3 A composite film of lop 200Op T-die Polyester resin paint 2 0 p Roll coating 220 0 C modified polyethylene and polyethylene Comparative Acryl-modified 20 p Roll coating 240'C 50 sec Example 1 vinylidene fluoride resin paint 2 Vinyl chloride film 2 0 0 p Filmlamination 3 A comnposi tefi Im of lS50 T-diemodified polyethylene and ____polyethylene.
4 Polyester resin paint 15 P Roll coating 220'C 30 sec 14
S.
a C S.
C
a a a a a. a a. a Table 2 TestItes ad coditonsExamle Exmple2 Eampe 3 Comparative Comparative Comparative Comparative Tes Iem ad oniton Eampe Eamle2 xapl 3 Example 1 Example 2 Example 3 Example 4 Formability Vise bending test OT 5/5 5/5 4/4 4/4 5/5 5/541 2T 5/5 5/5 4/4 5/5 5/5 5/544 Scratch resistance Pencil hardness test 5B 53 5B F 6B 6B H Adhesion Cross-cut test Tape peeling 100/100 100/100 100/100 100/100 100/100 100/100 100/100 Cross-cut test after 2 hrs of immersion in boiled water Tape peeling 100/100 100/100 100/100 100/100 100/100 100/100 100/100 15 S S S* S Table 2 Test items and conditions Example I Example 2 ExamPple 3 Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Corrosion resistance Salt spray test 3000 hrs Flat portion 0 0 0 0 0 0A Cross-cut portion (MM) 1 1 1 2 1 1 2T formed portion 0 0 0 X 0 0 X Humidity exposure test 3000 hrs Flat portion 0 0 0 0 0 0A Cross-cut portion (MM) 0 0 0 1 3-5 0 4 2T formed portion 0 0 0 A0 0 X Weatherability DSW test 2000 hrs 0 0 A0 x xA 16 The following is a description of the tests and conditions employed for the tests, and the standards for the evaluation of the test results: The formability tests OT and 2T by a vise were each conducted by bending each sample by an angle of 180 degrees with the vise, and the results were rated by scores,,as explained below. Score 5 means that no cracking was found, score 4 means that there was no peeling of the coating film despite its cracking, score 3 means that less than 30% of the film peeled off, score 2 means that from inclusive, to 70%, exclusive, of the film peeled off, and score 1 means tha-+ 70% or more of the film peeled off. The lower scores indicate the results of evaluation made after o.
forced peeling with a plastic tape.
^5 The scratch resistance was determined by conducting e a pencil hardness test in accordance with JIS D-0202.
The adhesion was determined by conducting a crosso0* cut test in accordance with JIS K-5400.
The corrosion resistance was determined by conducting a salt spray test and a humidity exposure test for 3000 hours. The results of the tests on the flat portion *0 0 of each sample are shown by o when it did not swell at all, by when it swelled to some extent, and by x when it swelled heavily. The results of the tests on the cross-cut portion are shown by the width of its swollen area in mm. The 17 results of the tests on the 2T formed portion are shown by o if it was not rusty at all, by A if it was somewhat rusty, and by x if it was very rusty.
The weatherability was determined by conducting 2000 hours of a test by a weatherometer in accordance with JIS K-5400. The results of the tests are shown by o if no change was found in color or luster, by 6 if some changes were found in color and luster, and by x if great changes were found.
As is obvious from the foregoing, this invention provides a coated metal sheet of high durability having, among others, excellent corrosion resistance, weatherability and formability which cannot be attained by any conventional surface-treated steel sheet, by employing a polyolefin resin and a paint for a colored steel sheet in combination, so 0 that the paint for a colored steel sheet may compensate for the drawbacks of the polyolefin resin, and vice versa.
Thus, it has a very high level of industrial utility.
eeoc *e *g I• e 18

Claims (26)

1. A surface treated metal sheet of high durability comprising: a chemically treated metal sheet; an undercoat layer on the metal sheet, the undercoat layer comprising an organic resin paint containing a rust-inhibitive pigment; an intermediate coating layer on the undercoat layer, the intermediate coating layer comprising a two- layer composite extruded film which comprises an adhesive layer of modified polyolefin resin on the undercoat layer and a polyolefin resin layer on the adhesive layer; and a topcoat layer on the intermediate coating layer, the topcoat layer comprising a topcoat paint selected 15 from an acrylic resin paint, a urethane resin paint, a polyester resin paint and a fluororesin paint.
2. A surface treated metal sheet as claimed in claim 1 wherein the metal sheet is a galvanised steel S* •sheet, a steel sheet plated with aluminium-zinc alloy, a steel sheet plated with aluminium, an aluminium sheet or a stainless steel sheet.
3. A surface treated metal sheet as claimed in claim 1 or claim 2 wherein the chemically treated metal sheet is a phosphoric acid or chromic acid treated metcl sheet.
4. A surface treated metal sheet as claimed in any one of the preceding claims wherein the organic resin paint is an epoxy resin paint or a polyester resin paint.
A surface treated metal sheet as claimed in any one of the preceding claims wherein the rust-inhibitive pigment comprises a chromium compound.
6. A surface treated metal sheet as claimed in claim 5 wherein the chromium compound is strontium chromate or zinc chromate.
7. A surface treated metal sheet as claimed in any one of the preceding claims wherein the undercoat layer is 1-20 microns thick. S:22749A/700 20
8. A surface treated metal sheet as claimed in any one of the preceding claims wherein the polyolefin resin layer is a polyethylene or polypropylene resin layer.
9. A surface treated metal sheet as claimed in any one of the preceding claims wherein the intermediate coating layer further comprises a heat stabiliser and/or a light stabiliser.
A surface treated metal sheet as claimed in claim 9 wherein the heat stabiliser is selected from phenol, phosphorous, hindered phenol and thioether compounds and the light stabiliser is selected from benzotriazole, benzophenone, acrylate, oxanilide, nickel complex or hindered amine compound.
11. A surface treated metal sheet as claimed in any 15 one of the preceding claims wherein the intermediate coating layer is 50-500 microns thick.
12. A surface treated metal sheet as claimed in claim 11 wherein the adhesive layer is 5-30 microns thick e a and the polyolefin resin layer is 45-495 microns thick.
13. A surface treated metal sheet as claimed in any one of the preceding claims wherein the topcoat layer is 5-35 microns thick.
14. A surface treated metal sheet substantially as herein described with reference to any non-comparative 25 Example.
A process for manufacturing a surface treated metal sheet of high durability, the process comprising the steps of: subjecting a metal sheet to a chemical treatment to form a chemically treated metal sheet; applying an organic resin paint containing a rust- inhibitive pigment onto the chemically treated metal sheet and drying the organic resin paint to form an undercoat layer on the chemically treated metal sheet; extruding a molten modified polyolefin resin and a molten polyolefin resin simultaneously in two layers from 0 an extruder through a T-die to form an intermediate coating layer on the undercoat layer, the intermediate JT' S:22749A/700 21 coating layer comprising an adhesive layer of the modified polyolefin resin on the undercoat layer and a layer of the polyolefin resin on the adhesive layer; and applying a topcoat paint selected from an acrylic resin paint, a urethane resin paint, a polyester resin paint and a fluororesin paint onto the intermediate coating layer and drying the topcoat paint to form a topcoat layer on the intermediate coating layer.
16. A process as claimed in claim 15 wherein the chemical treatment is a phosphoric acid or chromic acid treatment.
17. A process as claimed in claim 15 or claim 16 wherein the organic resin paint and the topcoat paint are applied by roll coating. 15
18. A process as claimed in any one of claims 15-17 wherein the organic resin paint is dried by heating at a ttemperature of 180 0 C-240 0 C.
19. A process as claimed in any one of claims 15-18 wherein the topcoat paint is dried by heating at a temperature of 200 0 C-250 0 C.
20. A process as claimed in any one of claims 15-19 further comprising the step of subjecting the intermediate coating layer to flame or corona discharge treatment prior to application of the topcoat paint. 25
21. A process as claimed in any one of claims 15-20 wherein the metal sheet is a galvanised steel sheet, a steel sheet plated with aluminium-zinc alloy, a steel sheet plated with aluminium, an aluminium sheet or a stainless steel sheet.
22. A process as claimed in any one of claims 15-21 wherein the organic resin paint is an epoxy resin paint or a polyester resin paint.
23. A process as claimed in any one of claims 15-22 wherein the rust-inhibitive pigment comprises a chromium compound.
24. A process as claimed in claim 23 wherein the S chromium compound is strontium chromate or zinc chromate.
S:22749A/700 22 A process as claimed in any one of claims 15-24 wherein the polyolefin resin is polyethylene resin or polypropylene resin.
26. A process for manufacturing a surface treated metal sheet substantially as herein described with reference to any non-comparative Example. DATED this 6th day of December 1995 TAIYO STEEL CO., LTD By its Patent Attorneys GRIFFITH HACK CO. S e 4 S o* A A S:22749A/700 'ABSTRACT OF THE DISCLOSURE A surface-treated metal sheet of high durability having excellent corrosion resistance, weatherability and formability, and intended mainly for use as a material for outdoor construction. It has a chemically conversion treated surface, and carries thereon an undercoat layer of an organic resin paint containing a rust-inhibitive pigment, an intermediate coating layer consisting of an'adhesive layer of a modified polyolefin resin and an intermediate layer of a polyolefin resin, and formed by the simultane- ous T-die extrusion of those resins, and a topcoat layer of an acrylic, urethane or polyester resin paint, or a fluororesin paint. A process for manufacturing it is *alo also disclosed. *o 0 *r
AU38296/93A 1992-06-12 1993-04-29 Surface-treated metal sheet of high durability and a process for manufacturing the same Ceased AU666934B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP4177656A JP2671718B2 (en) 1992-06-12 1992-06-12 Highly durable surface-treated metal plate and method for producing the same
JP4-177656 1992-06-12

Publications (2)

Publication Number Publication Date
AU3829693A AU3829693A (en) 1993-12-16
AU666934B2 true AU666934B2 (en) 1996-02-29

Family

ID=16034807

Family Applications (1)

Application Number Title Priority Date Filing Date
AU38296/93A Ceased AU666934B2 (en) 1992-06-12 1993-04-29 Surface-treated metal sheet of high durability and a process for manufacturing the same

Country Status (9)

Country Link
US (1) US5648126A (en)
EP (1) EP0578364B1 (en)
JP (1) JP2671718B2 (en)
KR (1) KR100228625B1 (en)
AU (1) AU666934B2 (en)
CA (1) CA2094346A1 (en)
DE (1) DE69306673T2 (en)
ES (1) ES2096861T3 (en)
FI (1) FI104904B (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3228022B2 (en) * 1994-08-25 2001-11-12 大洋製鋼株式会社 Composite metal plate and method of manufacturing the same
MY136271A (en) * 1994-12-29 2008-09-30 Toyo Kohan Co Ltd A resin-coated metal sheet with higher vivid reflectivity having the excellent workable adhesion strength
US6660086B1 (en) * 2000-03-06 2003-12-09 Innovative Coatings, Inc. Method and apparatus for extruding a coating upon a substrate surface
US20070020475A1 (en) * 2005-07-21 2007-01-25 Prince Kendall W Primed substrate and method for making the same
WO2007132600A1 (en) * 2006-05-17 2007-11-22 Nissan Motor Co., Ltd. Ultrahigh strength steel sheet and strength part for automobile utilizing the same
US9289795B2 (en) 2008-07-01 2016-03-22 Precision Coating Innovations, Llc Pressurization coating systems, methods, and apparatuses
US9616457B2 (en) 2012-04-30 2017-04-11 Innovative Coatings, Inc. Pressurization coating systems, methods, and apparatuses
KR101459364B1 (en) * 2013-07-22 2014-11-10 포스코강판 주식회사 A method of manufacturing of lamineted steel sheet with excellent image clarity
WO2015190628A1 (en) * 2014-06-11 2015-12-17 포스코강판 주식회사 Method for manufacturing multi-laminated color steel sheet
WO2015190629A1 (en) * 2014-06-11 2015-12-17 포스코강판 주식회사 Color steel plate and method for manufacturing same

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4888244A (en) * 1985-09-10 1989-12-19 Kansai Paint Co., Ltd. Process for forming composite coated film

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2636257A (en) * 1950-09-23 1953-04-28 Westinghouse Electric Corp Protective finish for metals
GB1020740A (en) * 1963-08-29 1966-02-23 Hercules Powder Co Ltd Improvements in or relating to process for bonding a polyolefin to metal
US4407689A (en) * 1979-12-21 1983-10-04 Toyo Ink Manufacturing Co., Ltd. Process for production of laminated member
JPS56152765A (en) * 1980-04-30 1981-11-26 Kansai Paint Co Ltd Formation of olefin resin coating film
US4358493A (en) * 1981-01-29 1982-11-09 Toyo Ink Manufacturing Co., Ltd. Cans
US4606953A (en) * 1983-06-23 1986-08-19 Nippon Steel Corporation Polypropylene coated steel pipe
JPS6063243A (en) * 1983-09-19 1985-04-11 Mitsui Petrochem Ind Ltd Highly adhesive composition
US4755434A (en) * 1984-12-07 1988-07-05 Kansai Paint Co., Ltd. Process for coating metallic substrate
JPS63165134A (en) * 1986-12-26 1988-07-08 川鉄鋼板株式会社 polyolefin laminate
US4871591A (en) * 1987-01-27 1989-10-03 Kansai Paint Company, Limited Finish coating method

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4888244A (en) * 1985-09-10 1989-12-19 Kansai Paint Co., Ltd. Process for forming composite coated film

Also Published As

Publication number Publication date
KR100228625B1 (en) 1999-11-01
JP2671718B2 (en) 1997-10-29
EP0578364A2 (en) 1994-01-12
EP0578364B1 (en) 1996-12-18
EP0578364A3 (en) 1994-07-06
FI931856A0 (en) 1993-04-23
US5648126A (en) 1997-07-15
DE69306673D1 (en) 1997-01-30
JPH0639964A (en) 1994-02-15
FI104904B (en) 2000-04-28
FI931856L (en) 1993-12-13
AU3829693A (en) 1993-12-16
CA2094346A1 (en) 1993-12-13
DE69306673T2 (en) 1997-05-28
KR940000234A (en) 1994-01-03
ES2096861T3 (en) 1997-03-16

Similar Documents

Publication Publication Date Title
AU666934B2 (en) Surface-treated metal sheet of high durability and a process for manufacturing the same
EP0698484B1 (en) Composite metal sheet and method for producing it
JPH0341342B2 (en)
MX2008014074A (en) Sheet steel provided with a corrosion protection system and method for coating sheet steel with such a corrosion protection system.
JPH0356112B2 (en)
JP3376949B2 (en) Solar heat reflective surface treated metal plate
JPH05220449A (en) Highly durable coated steel panel having damaged part corrosion resistance and processability and production thereof
US4317857A (en) Composite coated metal sheet
JP3347657B2 (en) Pre-coated metal sheet for outdoor use
JP2001335738A (en) Painted metal sheet and coating composition therefor
KR20200059364A (en) Primer Coating Composition for Manufacturing Pre-Coated Metal Color Sheet and Color Sheet Using the Same
KR20190062944A (en) Coated steel sheet having high corrosion resistance and method for manufacturing the same
JP3686513B2 (en) Manufacturing method of coated metal plate with smooth uneven appearance
JPH0132774B2 (en)
JPS59179339A (en) Precoated steel plate
JPH0510223B2 (en)
JPS59179340A (en) Precoated steel plate
KR100550832B1 (en) Highly corrosion-resistant thin water-soluble organic coating agent for zinc or zinc-aluminum alloy steel sheet having adhesion with polyethylene foam, polystyrene foam and polyurethane foam, and method for manufacturing steel sheet coated with the same
CA1125590A (en) Composite coated metal sheet
DE2010358A1 (en) Composite steel and aluminium sheeting or - strips
JPH0819756A (en) Painted metal material with excellent weather resistance and workability
JP2004230559A (en) Highly durable painted steel sheet with excellent design
JPH07195613A (en) Designed pre-coated steel sheet with excellent corrosion resistance on the end surface
JPS63293048A (en) Composite polyvinyl chloride resin and fluoroplastic covered metal material
JPH10226015A (en) Painted metal sheet having smooth uneven appearance and method for producing the same

Legal Events

Date Code Title Description
MK14 Patent ceased section 143(a) (annual fees not paid) or expired